scholarly journals Reaction Pathway for Coke-Free Methane Steam Reforming on a Ni/CeO2 Catalyst: Active Sites and the Role of Metal–Support Interactions

ACS Catalysis ◽  
2021 ◽  
pp. 8327-8337
Author(s):  
Agustín Salcedo ◽  
Pablo G. Lustemberg ◽  
Ning Rui ◽  
Robert M. Palomino ◽  
Zongyuan Liu ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Active Sites ◽  
Reaction Pathway ◽  
Methane Steam Reforming ◽  
Methane Steam ◽  
Metal Support ◽  
Metal Support Interactions

Effect of Catalytic Distribution on the Performance of Microreactor for Hydrogen Production through Methane Steam Reforming

2010 ◽  
Vol 156-157 ◽  
pp. 873-876 ◽  
Author(s):  
Feng Wang ◽  
Zi Long An ◽  
Bo Qi ◽  
Jing Zhou
Keyword(s):  
Steam Reforming ◽  
Active Sites ◽  
Flow Direction ◽  
Space Velocity ◽  
H2 Production ◽  
Methane Steam Reforming ◽  
Reactor Performance ◽  
Methane Steam ◽  
Site Density ◽  
Availability Ratio

The effect of catalyst coating distributing on the reactor performance for methane steam reforming(MSR) was numerically investigated. In calculation, the amount catalyst loaded on the microreactor wall was fixed but the catalyst active site density was distributed according to arithmetic progression along the flow direction. Results show that it is possible to get the higher conversion of CH4 and output of H2 due to the higher availability ratio of catalyst surface active sites at this distribution. And this distribution effect is more remarkable at higher space velocity or lower reaction temperature, however, there exists an optimal distribution which can reach the highest CH4 conversion and H2 production at 900K.

An Analysis of Heat Transfer Processes in an Internal Indirect Reforming Type Solid Oxide Fuel Cell

2010 ◽  
Author(s):  
Grzegorz Brus ◽  
Zygmunt Kolenda ◽  
Shinji Kimijima ◽  
Janusz S. Szmyd
Keyword(s):  
Steam Reforming ◽  
Solid Oxide ◽  
Methane Steam Reforming ◽  
Oxide Fuel ◽  
Carbon Formation ◽  
Internal Reforming ◽  
Thermal Boundary Conditions ◽  
Methane Steam ◽  
Fuel Flow ◽  
Metal Support

This paper presents experimental and numerical studies on the fuel reforming process on an Ni/YSZ catalyst. Nickel is widely known as a catalyst material for Solid Oxide Fuel Cells. Because of its prices and catalytic properties, Ni is used in both electrodes and internal reforming reactors. However, using Ni as a catalyst carries some disadvantages. Carbon formation is a major problem during a methane/steam reforming reaction based on Ni catalysis. Carbon formation occurs between nickel and metal-support, creating fibers which damage the catalytic property of the reactor. To prevent carbon deposition, the steam-to-carbon ratio is kept between 3 and 5 throughout the entire process. To optimize the reforming reactors, detailed data about the entire reforming process is required. In the present paper kinetics of methane/steam reforming on the Ni/YSZ catalyst was experimentally investigated. Measurements including different thermal boundary conditions, the fuel flow rate and the steam-to-methane ratios were performed. The reforming rate equation derived from experimental data was used in the numerical model to predict synthetic gas composition at the outlet of the reformer.

scholarly journals The role of metal–support interaction for CO-free hydrogen from low temperature ethanol steam reforming on Rh–Fe catalysts

2017 ◽  
Vol 19 (6) ◽  
pp. 4199-4207 ◽  
Author(s):  
Catherine K. S. Choong ◽  
Luwei Chen ◽  
Yonghua Du ◽  
Martin Schreyer ◽  
S. W. Daniel Ong ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Active Sites ◽  
Support Interaction ◽  
Metal Support Interaction ◽  
Free Hydrogen ◽  
Metal Support ◽  
Fe Catalysts ◽  
Ethanol Steam

Effect of metal–support interaction on the generation of Rh–FexOy active sites is investigated via various in situ techniques.

scholarly journals Reaction Pathway for Coke-Free Methane Steam Reforming on a Ni/CeO2 Catalyst: Active Sites and Role of Metal-Support Interactions

2021 ◽  
Author(s):  
Agustin Salcedo ◽  
Pablo Lustemberg ◽  
Ning Rui ◽  
Robert M. Palomino ◽  
Zongyuan Liu ◽  
...  
Keyword(s):  
High Activity ◽  
Steam Reforming ◽  
Active Sites ◽  
Density Functional ◽  
Ambient Pressure ◽  
Carbon Accumulation ◽  
Methane Steam Reforming ◽  
Severe Problem ◽  
Methane Steam ◽  
Water Activation

<p>Methane steam reforming (MSR) plays a key role in the production of syngas and hydrogen from natural gas. The increasing interest in the use of hydrogen for fuel cell applications demands the development of catalysts with high activity at reduced operating temperatures. Ni-based catalysts are promising systems because of their high activity and low cost, but coke formation generally poses a severe problem. Studies of ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) indicate that CH<sub>4</sub>/H<sub>2</sub>O gas mixtures react with Ni/CeO<sub>2</sub>(111) surfaces to form OH, CH<i><sub>x</sub></i> and CH<i><sub>x</sub></i>O at 300 K. All these species are easy to form and desorb at temperatures below 700 K when the rate of the MSR process accelerates. Density functional theory (DFT) modeling of the reaction over ceria-supported small Ni nanoparticles predicts relatively low activation barriers between 0.3–0.7 eV for the complete dehydrogenation of methane to carbon and the barrierless activation of water at interfacial Ni sites. Hydroxyls resulting from water activation allow CO formation via a COH intermediate with a barrier of about 0.9 eV, which is much lower than that through a pathway involving lattice oxygen from ceria. Neither methane nor water activation are rate-determining steps, and the OH-assisted CO formation through the COH intermediate constitutes a low-barrier pathway that prevents carbon accumulation. The interaction between Ni and the ceria support and the low metal loading are crucial for the reaction to proceed in a coke-free and efficient way. These results could pave the way for further advances in the design of stable and highly active Ni-based catalysts for hydrogen production.</p>

scholarly journals Rhodium-Catalyzed Methanation and Methane Steam Reforming Reactions on Rhodium-Perovskite Systems: Metal-Support Interaction

ChemCatChem ◽  
2016 ◽  
Vol 8 (12) ◽  
pp. 2057-2067 ◽  
Author(s):  
Ramona Thalinger ◽  
Thomas Götsch ◽  
Chen Zhuo ◽  
Walid Hetaba ◽  
Wolfgang Wallisch ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Support Interaction ◽  
Methane Steam ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Reforming Reactions

scholarly journals Reaction Pathway for Coke-Free Methane Steam Reforming on a Ni/CeO2 Catalyst: Active Sites and Role of Metal-Support Interactions

2021 ◽  
Author(s):  
Agustin Salcedo ◽  
Pablo Lustemberg ◽  
Ning Rui ◽  
Robert M. Palomino ◽  
Zongyuan Liu ◽  
...  
Keyword(s):  
High Activity ◽  
Steam Reforming ◽  
Active Sites ◽  
Density Functional ◽  
Ambient Pressure ◽  
Carbon Accumulation ◽  
Methane Steam Reforming ◽  
Severe Problem ◽  
Methane Steam ◽  
Water Activation

<p>Methane steam reforming (MSR) plays a key role in the production of syngas and hydrogen from natural gas. The increasing interest in the use of hydrogen for fuel cell applications demands the development of catalysts with high activity at reduced operating temperatures. Ni-based catalysts are promising systems because of their high activity and low cost, but coke formation generally poses a severe problem. Studies of ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) indicate that CH<sub>4</sub>/H<sub>2</sub>O gas mixtures react with Ni/CeO<sub>2</sub>(111) surfaces to form OH, CH<i><sub>x</sub></i> and CH<i><sub>x</sub></i>O at 300 K. All these species are easy to form and desorb at temperatures below 700 K when the rate of the MSR process accelerates. Density functional theory (DFT) modeling of the reaction over ceria-supported small Ni nanoparticles predicts relatively low activation barriers between 0.3–0.7 eV for the complete dehydrogenation of methane to carbon and the barrierless activation of water at interfacial Ni sites. Hydroxyls resulting from water activation allow CO formation via a COH intermediate with a barrier of about 0.9 eV, which is much lower than that through a pathway involving lattice oxygen from ceria. Neither methane nor water activation are rate-determining steps, and the OH-assisted CO formation through the COH intermediate constitutes a low-barrier pathway that prevents carbon accumulation. The interaction between Ni and the ceria support and the low metal loading are crucial for the reaction to proceed in a coke-free and efficient way. These results could pave the way for further advances in the design of stable and highly active Ni-based catalysts for hydrogen production.</p>

scholarly journals Differences in the Nature of Active Sites for Methane Dry Reforming and Methane Steam Reforming over Nickel Aluminate Catalysts

ACS Catalysis ◽  
2016 ◽  
Vol 6 (9) ◽  
pp. 5873-5886 ◽  
Author(s):  
Jessica L. Rogers ◽  
Michael C. Mangarella ◽  
Andrew D. D’Amico ◽  
James R. Gallagher ◽  
Michael R. Dutzer ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Active Sites ◽  
Dry Reforming ◽  
Methane Steam Reforming ◽  
Nickel Aluminate ◽  
Methane Dry Reforming ◽  
Methane Steam
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